The present invention relates to a safety and debris net system which are used as fall catching prevention type apparatus found in the construction industry, and deals more particularly with an improvement in the safety net material whereby the material realizes increased strength and effectiveness as a fall prevention device and deals as well with improvements in the connections between component parts of a net system and the securement devices used to secure the net system to supporting structure.
In the past safety net construction has been primarily limited to meshes made from nylon. While nylon meshes are still popular, some problems attendant to their use as using safety nets exist. First, nylon is not resistant to ultraviolet light and therefore must be treated to prevent the negative effects of exposure to such light. The treating process is usually accomplished by dyeing by dipping in a solution, and in this dyeing/dipping process causes shrinkage of the nylon. Even after this treatment is complete, the nylon material tends to undesirably stretch with use. Accordingly, in some applications, some sort of sag control measures must be incorporated into the support structure at the job sight to prevent net sagging . This is particularly important and needed in the application of netting which is used in tunnels or in bridges where the passage of vehicles below the netting, in particular trucks, could interfere or even cause entanglement with the moving vehicles below and thereby presenting a hazardous situation. Also, sag is undesirable because it would allow someone falling into a safety net to hit what was below it due to the travel which occurred at impact. Further, with the increasing concern for products which are made from environmentally safe processes, the dipping of a net into a chemical bath such as, described above, is likewise undesirable.
Also, in the connection between the debris and safety nets with the structure responsible for holding it in place, it is long been the practice to sew or lash the debris net or safety net to the border piece. This practice is very labor intensive and contributes to the major cost in net fabrication. Not only is the connection between the net and its border usually done by a sewing or lashing procedure, but also in the case with debris netting, the connecting rings which are used to connect the debris nets together have been sewn or lashed to the base material. The hem or border member of each debris net also defines an overlapping flap between successive debris net segments and must be sufficiently strong to bear the loads imposed on any connection it makes with another net. Likewise, the use of hooks which attach safety nets to supporting cables also use a hemming, lashing or sewing process which had the potential of becoming unraveled and hence the spacing between clip hooks would become undone. Additionally, hitherto the debris and the safety nets were fabricated as separate items, and thus were required to be assembled together at a given on-site location to assume the layered orientation, e.g., the debris net superimposed over the safety net. This process took time and added to labor expense. It also contributed to the need to provide a connection system which could orient these nets in this manner.
Accordingly, it is an object of the invention to provide a improved net of the type which is used as a safety net for personnel or as a rack guard or conveyor guards wherein the net mesh is connected to its supporting border in a manner which significantly reduces its manufacturing costs and production time.
Still a further object of the invention is to provide a combined debris and safety net which is fabricated as one unit thus avoiding the hitherto problems associated with assembling the two on site.
It is yet a further object of the invention to provide a net of the aforementioned type which is resistant to deterioration because of exposure to ultraviolet radiation hence making it unnecessary to color it by dyeing or treating which hitherto has been standard practice in the industry and avoids the problem of shrinkage of material due to such dyeing process as well as avoiding the negative effects of such treatment on the environment.
A further object of the invention is to provide an improved connection between a safety net and or a debris net with parameter structure which connects to static supports of a safety system.